Ectopic pancreatic adenocarcinoma in Meckel's diverticulum: a case report.

BACKGROUND: Malignant neoplasms arising from Meckel's diverticulum are rare and an adenocarcinoma in Meckel's diverticulum originating from ectopic pancreatic tissue is even rarer. Herein, we report a patient with an ectopic pancreatic adenocarcinoma in Meckel's diverticulum who was successfully treated with surgery and chemotherapy. CASE PRESENTATION: A woman in her sixties presented to another hospital with abdominal pain. Plain computed tomography suggested an abdominal tumor and she was referred to our hospital. Enhanced computed tomography revealed a 23-mm low-density tumor in the abdominal cavity. Surgery was performed with a tentative diagnosis of a mesenteric tumor, such as a gastrointestinal stromal tumor, schwannoma, or lymphoma. First, we inspected the peritoneal cavity with a laparoscope. This revealed numerous nodules in the small bowel mesentery, suggesting peritoneal dissemination. A 20-mm-diameter white tumor was found in the small intestine and diagnosed as a small intestinal cancer. The small intestine was partially resected laparoscopically through a small skin incision. The patient's postoperative course was uneventful, and she was discharged on postoperative day 9. Pathological examination revealed well-differentiated adenocarcinoma in the small intestine. The tumor had developed from a sac-like portion protruding toward the serosal side and had a glandular structure lined with flattened atypical cells. Neither pancreatic acinar cells nor islets of Langerhans were evident, suggesting a Heinrich type 3 ectopic pancreas. The final diagnosis was an adenocarcinoma originating from an ectopic pancreas in Meckel's diverticulum. After a smooth recovery, the patient commenced chemotherapy for pancreatic cancer. CONCLUSIONS: We present a very rare case of ectopic pancreatic carcinoma in Meckel's diverticulum.

Unilateral spatial neglect affected by right-sided stimuli in a three-dimensional virtual environment: A preliminary proof-of-concept study.

Unilateral spatial neglect (USN) is defined as the inability to attend and see on one side, which seriously interferes with daily life. Clinically, patients with left USN commonly demonstrate a striking immediate capture of attention from ipsilesional, right-sided items as soon as a visual scene unfolds (i.e., magnetic attraction [MA]). Therefore, this preliminary study utilized a three-dimensional (3D) virtual environment to evaluate the effects of eliminating stimuli in the rightward space and directing attention to the left on neglect symptoms. METHODS: Seven patients with USN participated in this study, and two types of visual stimuli were created: the numbers and objects in the 3D virtual environment. To eliminate the visual stimuli on the right side, a moving slit was introduced in the virtual environment. During the experiment, patients were required to orally identify each object and number both in moving and nonmoving slit conditions. RESULTS: A statistical comparison of scores with and without the moving slit in the 3D virtual space indicated significant changes in the object stimuli condition; however, no statistically significant difference was observed in the number stimuli condition. CONCLUSIONS: Masking the right side within the 3D virtual space increased the number of objects that can be recognized on the left side by patients with USN. The results may allow interventions in a virtual reality environment that closely resembles the patient's real-life space.Clinical Relevance-Magnetic attraction is a symptom seen in patients in clinical practice, but there is no method of rehabilitation. The proposed moving slit method is expected to be effective because it enables attention guidance in a three-dimensional space.

Neurorehabilitation Method for Preventing the Collapse of Internal Model: Verification of Unconscious Motor Change Caused by Implicit Error Involved in Multimodal Sensory FBs(Feedbacks).

It remains challenging for patients with stroke to regain the proper gait they had before stroke onset. In this study, one of the significant reasons for the problem is assumed to be the collapse of patients' internal model. Therefore, this study aimed to propose a method for lower-limb rehabilitation in the acute phase to prevent the collapse of the internal model and simultaneously promote voluntariness.To verify the effect of the proposed method and determine the optimal FB conditions, a supine pseudo-walking system has been developed providing multimodal sensory FBs, including somatosensory FB (walking on the walking robot), load transfer FB (plantar vibration provided by the robot), and visual FB (walking scene shown in virtual reality).First, the implicit error range of each sensory FB that was unable to recognize was investigated according to Weber's law. Subsequently, 12 participants were asked to perform 12 steps of walking exercise in the system to evaluate the unconscious motor-changing effect due to different/multimodal FBs. Errors were presented at the 7th step in either three FBs in the ratio determined or their combinations (two or three types of FBs simultaneously changing).Second, to examine whether the effect can last and influence the motion after the training, a pre-post comparison test was performed with the training in the middle, wherein implicit errors were presented in the three kinds of FBs.The results show that presenting implicit error can cause motor change, and multiple types of FBs may have a better effect. The statistical data of 12 participants of the pre-post comparison test show that the average integrated electromyogram in the post-test appears significantly larger than that in the pre-test. The result indicates that the motor-changing effect of the proposed method has a subsequent influence on motion and shows the possibility of the future application of the proposed method to the rehabilitation field.

Fractal Dynamics in a Whole-Body Dynamic Balance Sport, Slacklining: A Comparison of Novices and Experts.

The present study investigated whether fractal dynamics can be observed during single-leg standing on a slackline. We also examined whether the temporal structure differs with skill level. To address these questions, we compared single-leg standing performance between novices (N=5) and experts (N=5) in terms of fractal dynamics in both ankles (i.e., stance and swing legs), center of mass, and head acceleration time series using detrended fluctuation analysis. Participants were required to perform single-leg standing on a slackline. To collect motion data while slacklining, we used a three-dimensional motion capture system and obtained time-series data on the position. We conducted detrended fluctuation analysis on the original acceleration time series and random shuffled time series to examine the fractal dynamics in each body part's fluctuation. Results suggest that experts showed persistent temporal structure in the swinging leg, center of mass, and head fluctuations in the horizontal direction, while that of novices did not differ from random fluctuations. These findings revealed that experts performing a single-leg standing task on a slackline show fractal dynamics. This might reflect their flexible or adaptive exploratory behavior in the performer-environment system and contribute to the dynamic stability of whole-body dynamic balancing.

Impact of Joint Fixation on Postural Dynamics during Single-Leg Stance.

We investigated the relationship between the mechanical degrees of freedom (DoF) and its postural dynamics. The joint DoF was fixed to constrain the mechanical DoF. Nine participants were required to perform a single-leg stance task. The center of pressure trajectory data was analyzed. Ankle fixation induced a larger amount of variability in the anteroposterior direction, and less dimensionality and complexity in the mediolateral direction. These results suggest that the ankle joint fixation caused limited postural sway in the mediolateral direction; therefore, functional DoF and complexity decreased. In contrast, it increased the amount of postural sway variability in the anteroposterior direction. Our findings imply a direct relationship between the mechanical DoF of the human movement system and its postural dynamics.

Quantification of Unilateral Spatial Neglect Symptoms Based on Identification of Exploratory Ability.

Unilateral spatial neglect (USN) is the failure to report, respond, or orient to novel or meaningful stimuli presented on the side opposite a brain lesion. In our previous study, we reported that the ability of patients with USN to perform when the neck was fixed (called cognitive ability) was different from that when the neck was not fixed (called exploratory ability). However, the exploratory ability index has not been clarified, and cognitive and exploratory abilities have not been quantified. Thus, in this study, we identified neck movement as an exploratory ability index for patients with USN. Furthermore, we proposed equations to quantify cognitive and exploratory abilities and suggested that these equations can be used to understand patients' neglect symptoms in more detail. These findings revealed that the two evaluations of cognitive and exploratory abilities are crucial in USN evaluation and are key to individualizing intervention for each patient.

A Pneumatic Artificial Muscle and Spring Combination System that Assists Ankle Rocker and Transforms Energy into Push-Off Support: A Feasibility Study in Heathy Participants.

Insufficient push-off is a common problem for stroke hemiplegia patients. Assistive systems using extension spring to store energy during stance phase of gait to provide push-off assistance have been developed. However, patients could also suffer poor ankle rocker function; that is, poor dorsiflexion movement in stance phase. In such case, the spring could reversely become a burden for ankle movement. In this research, we proposed a system that combines a pneumatic artificial muscle and a tension spring. The artificial muscle mimics a human's tibialis anterior muscle, while the spring mimicking the Achilles tendon. Upon foot flat event of gait, the artificial muscle contracted to assist ankle rocker function and stretched the spring to store energy simultaneously. After heel off, the artificial muscle extended and the spring was released to provide push-off assistance. A feasibility study in seven healthy participants was conducted to verify assistance effects on their ankle rocker function and push-off movements. The results show significant increase in ankle rocker angle, push-off angle, and push-off torque compared with those during normal walk when the participants were assisted by our system. Therefore, we believe that the proposed system has great potential to assist stroke survivors with problems of poor ankle rocker function and push-off movements.

A Proposal for a New Index to Quantify the Ratio of Near and Far Spatial Neglect Using Immersive Virtual Reality Technology: A Technical Report.

Unilateral spatial neglect (USN) is defined as impaired attention to sensory stimuli on one side, which can exist for near and far spaces combined or independently. Thus, quantifying both near- and far-space neglect is crucial. This study aims to propose an index to quantify the near/far spatial neglect ratio to describe the USN symptoms' characteristics in each patient using immersive virtual reality (VR) technology. An object-detecting task was performed for five USN patients in a three-dimensional VR space. The examiner recorded the positional data of the objects that were recognized by the USN patient using coordinate data. The near/far ratio (NFRatio) was calculated using the proposed equation to quantify the difference in neglect severity in near and far spaces of each patient. Among the patients, four tended to have greater far-space neglect, and one tended to have greater near-space neglect. Moreover, the near/far spatial neglect ratio was shown to vary according to height. This is the first study to propose immersive VR to quantify the near and far spatial neglect. However, further study is needed to assess its reliability and validity and describe its clinical usability. Clinical Relevance- In clinical practice USN symptoms cause neglected symptoms in 3D space so the proposed system will be of high clinical significance if 3D assessment is realized.

The influence of a vibrotactile biofeedback system on postural dynamics during single-leg standing in healthy older adults.

The effectiveness of sensory substitution technology, such as haptic-based vibrotactile biofeedback (VBF), has been verified for balance training and rehabilitation. However, whether VBF training changes postural dynamics in older people remains unknown. This study investigated the influence of VBF training on postural dynamics during single-leg standing in older adults, using detrended fluctuation analysis (DFA). Twenty older adults participated in this study. Measurement of postural sway comprised three phases: first measurement session as a baseline test, postural training (day 1), and second measurement session (day 2). The BF group received BF training during the balance training session, while the control group practiced single-leg stance without BF. The center of pressure (CoP) trajectory was recorded in the first measurement session (pre) and second measurement session (post) at 50 Hz. DFA revealed the presence of two linear scaling regions in the CoP, indicating the presence of fast- and slow-scale fluctuations. For the BF group, slow-scale postural dynamics revealed more anti-persistent behavior after training in the anterior-posterior direction. However, the control group showed a change toward more random dynamics after training. These different influences suggest that the BF system might improve error correction strategies during single-leg standing for older adults, while single-leg standing training without the BF system might cause the loss of controllability in single-leg standing. Further, the results of the DFA are discussed in the context of balance training using VBF.

Walking through a narrow opening improves collision avoidance behavior in a patient with stroke and unilateral spatial neglect: an ABA single-case design.

We investigated the effect of a 3-week intervention-wherein a patient with unilateral spatial neglect walks through a narrow opening while entering from the contralesional side-to improve walking ability or ADL. A 66-year-old man was diagnosed with right parietal subcortical hemorrhage. We used an ABA single-case design; period B was set as the intervention. The intervention improved the continuous walking distance and balance ability and decreased the number of collisions when walking through the narrow opening; however, it exerted minimal effect on ADL. Thus, the intervention may effectively improve continuous physical or spatial attention behavior, regardless of ADL improvement.

Development of a vibrotactile cueing device that implicitly increases walking speed during gait training in stroke patients: an observational case series study.

One of the main sequelae of stroke is difficulty walking, which is characterised by decreased walking speed and asymmetrical walking patterns. Physical therapists often rely on explicit motor learning strategies, i.e., providing mainly verbal instructions for how movements should be performed. However, the voluntary movement induced by explicit instruction may lead to associated unintended muscle contractions or higher cognitive demand, which could be detrimental. We introduce a vibrotactile cueing device that implicitly improves walking speed. The stroke patient walks while alternating vibrational cues are given to the left and right sides of their waist. At each specified step, cueing frequency increases in the cueing group without the patient's awareness. The four patients in the cueing group did not notice the increase in walking speed during training; however, we observed an improvement in walking speed and cadence in patients using the proposed cueing system, which was maintained during the posttest phase. Additionally, patients using the cueing system were able to suppress excessive compensatory movements during training compared with patients who did not use the system. This case series study indicates that the proposed system for gait rehabilitation of stroke patients can enable an increase in walking speed without excessive effort.

Investigation of optimal gait speed for motor learning of walking using the vibro-tactile biofeedback system.

In stroke patients, sensory loss often reduces the sensation of ground contact, which impairs motor learning during rehabilitation. In our previous study, we proposed a vibro-tactile biofeedback system (which we called the perception-empathy biofeedback system) for gait rehabilitation. The results of our 9-week pilot clinical test suggested that patients who had reached the autonomous phase in gait learning had difficulty noticing the external vibratory feedback provided by the biofeedback system, leading to ineffective intervention. We considered the possibility that slower walking speed might return the patient to the association phase and allow patients to improve their gait according to the sensory feedback provided. Thus, in this research, a method based on reducing walking speed to guide patients' attention was derived. A pilot clinical trial shows that there is a statistically significant increase of ankle dorsiflexion in the initial contact phase and increase of ankle plantarflexion in the push-off phase after vibro-tactile biofeedback system intervention with speed reduction, compared to intervention without speed reduction. The results suggest that, by reducing their walking speed during intervention, patients return to the association phase and recognize external vibratory feedback, which may result in better intervention effects.Clinical Relevance-This study provides knowledge about the optimal walking speed when using vibro-tactile biofeedback for motor learning in stroke patients.

Effects of Assisted Dorsiflexion Timing on Voluntary Efforts and Compensatory Movements: A Feasibility Study in Healthy Participants.

In previous research, we found that modulating the assistance timing of dorsiflexion may affect a user's voluntary efforts. This could constitute a focus area based on assistive strategies that could be developed to foster patients' voluntary efforts. In this present study, we conducted an experiment to verify the effects of ankle dorsiflexion assistance under different timings using a high-dorsiflexion assistive system. Nine healthy and young participants wore a dorsiflexion-restrictive device that enabled them to use circumduction or steppage gaits. On the basis of the transition from the stance to the swing phase of the gait, the assistance timings of the high-dorsiflexion assistive system were set to have delays, which ranged from 0 to 300 ms. The index results from eight out of nine participants evaluated compensatory movements and revealed positive strong/moderate correlations with assistance delay times (r = 0.627-0.965, p <.001), whereas the other participants also performed compensatory movement when dorsiflexion assistance timing was late. Meanwhile, the results from tibialis anterior surface electromyography from six out of nine participants showed positive strong/moderate correlations with dorsiflexion assistance delay times (r = 0.598-0.922, p <.001), indicating that tuning the assistance timing did foster these participants' voluntary dorsiflexion movements. This result indicates that there should be a trade-off between ensuring voluntary dorsiflexion movements and preventing incorrect gait patterns at different assistance timings. The findings of this feasibility study indicate the potential of developing an adaptive control method to ensure voluntary efforts during robot-assisted gait rehabilitation based on assistance timing modification. A new assistance mechanism should also be required to stimulate and motivate a patient's voluntary efforts and should reinforce the effects of active gait rehabilitation.

Effect of gait training using Hybrid Assistive Limb on gait ability and the risk for overwork weakness in the lower limb muscles in patients with neuromuscular disease: a proof-of-concept study.

BACKGROUND: Few previous studies have reported the efficacy of robot rehabilitation for improving gait ability or its adverse events in patients with neuromuscular diseases. AIM: The aim of the present study was to elucidate the effects of gait training with a hybrid assistive limb (HAL) on gait ability and to investigate serum enzyme levels associated with skeletal muscle damage. DESIGN: Proof-of-concept study. SETTING: Department of rehabilitation medicine in university hospital. POPULATION: Twenty-one patients with neuromuscular disease (NMD, 13 males and 8 females, mean age of 60.6 years). METHODS: All patients underwent 1 to 5 series of gait rehabilitation which consisted of 9 sessions of HAL training. Gait ability was assessed with the 10-meter walk test and the 2-min walk test before and after HAL training, while serum creatine phosphokinase, aspartate aminotransferase, and lactic acid dehydrogenase values were measured before, midway through, and after HAL training. RESULTS: Gait velocity and step length for 10-meter walk test, and 2-min walk distance were significantly improved after HAL gait training. There was no significant change in serum level of all 3 measured enzymes between the three time points. CONCLUSIONS: HAL gait training with the practical setting as this study improved gait ability in patients with progressive NMD and did not damage skeletal muscle, as indicated by no significant change in serum level of muscle enzymes. CLINICAL REHABILITATION IMPACT: Robot assisted gait training could be safely applied to the patients with NMD, as one of the effective rehabilitation programs to improve gait ability.

Bimanual Coordination in a Whole-Body Dynamic Balance Sport, Slacklining: A Comparison of Novice and Expert.

As previous studies have suggested that bimanual coordination is important for slacklining, the authors questioned whether this important skill plays a role in the performance of a fundamental task of slacklining. To address this question, the authors compared single-leg standing on the slackline between novices and experts in terms of bimanual coordination dynamics within a dynamical systems framework using relative phase and recurrence quantification analysis measures. Five novices and five experts participated in the experiment. Participants were required to perform single-leg standing on a slackline. To collect motion data while slacklining, the authors used a 3D motion capture system and obtained time series data on the wrist position of both hands. The authors compared bimanual coordination dynamics between novices and experts. Although this preliminary study was limited in its sample size, the results suggest that experts tend to show a more antiphase coordination pattern than novices do and that they can more sustainably coordinate their hands compared with novices in terms of temporal structure in diagonal-related recurrence measures (i.e., maxline, mean line, and percentage determinism).

A Haptic-Based Perception-Empathy Biofeedback System with Vibration Transition: Verifying the Attention Amount.

In this paper, a perception-empathy biofeedback (PEBF) system is proposed that supplements the foot pressure status of a paralyzed foot with a wearable vibrotactile biofeedback (BF) vest to the back. Improvements in the ankle dorsiflexion and push-off movement in the swing phase and pre-swing phase, respectively, can be expected after using the proposed system. However, the results of the 3 week pilot clinical tests suggest that significant improvement is only observed for the push-off movement. It is assumed that the attention required to recognize the BF was beyond the ability of the patients. In this paper, a dual task (40 s walking and performing mental arithmetic at the same time) was conducted with the following conditions: no vibrations and providing BF to the lower back and the entire back. According to the results, the ankle joint angle of the paralyzed side at push-off under the entire back condition is statistically significant (p = 0.0780); however, there are no significant changes under the lower back condition (p = 0.4998). Moreover, the ankle joint angle of the paralyzed side at the initial contact is statistically significant with respect to the lower back condition (p = 0.0233) and shows a significant trend for the entire back condition (p = 0.0730). The results suggest that the limited attention capacity of hemiplegic patients fails to improve both dorsiflexion and push-off movements; moreover, ankle motion can be promoted if attention is concentrated on recognizing focalized vibratory feedback patterns.

Development and proof of concept of an immersive virtual reality system to evaluate near and far space neglect in individuals after stroke: A brief report.

BACKGROUND: Unilateral spatial neglect (USN) is defined as impaired attention to sensory stimuli on one side. The symptoms can exist for near and far spaces combined or independently. Thus, it is important to evaluate both possibilities in a clinical environment. OBJECTIVE: To develop a tractable immersive virtual reality (iVR) system that can evaluate both near and far space neglect along with a proof of concept study to determine whether near and far spatial neglect could be described in an actual patient with USN. METHODS: An object-detecting task was developed in a three-dimensional virtual reality space. The examiner recorded the positional data of objects that were recognized by the patient with USN using coordinate data. RESULTS: The system could be used to detect near and far space neglects in a patient with USN. No side effects such as vertigo were seen during measurement. This patient showed that the angle for recognition was significantly larger for near space than far space, and exhibited a tendency for the angle of recognition to increase with lower height. CONCLUSIONS: Our proof of concept study indicated the possibility of applying an evaluation system that separates far and near space neglect using iVR.

Identification of Spring Coefficient for Heel Rocker Function Support Based on Estimated Dorsiflexion Torque.

In previous research, we have developed a high-dorsiflexion assistive robotic technology aiming for gait rehabilitation targeting on ankle dorsiflexion movement. A McKibben-type artificial muscle is applied to provide large dorsiflexion force while adding little weight to the device. This ensures the foot clearance before initial stance phase in gait. Meanwhile, a tension spring is deployed in series with the artificial muscle to support heel rocker function in loading response phase. Suitable spring coefficient for each individual differs according to ankle's dorsiflexion torque in loading response. An unsuitable spring would lead to knee deviation in this phase. In this study, we derived an identification equation to determine a suitable spring coefficient for individuals based on estimation of dorsiflexion torque required to support. An evaluation test on healthy objects was conducted, which shows no negative effects on participants' knee angles with the identified spring coefficient.

Using a Vibrotactile Biofeedback Device to Augment Foot Pressure During Walking in Healthy Older Adults: A Brief Report.

Human movement based on sensory control is significant to motor task performance. Thus, impairments to sensory input significantly limit feedback-type motor control. The present study introduces a vibrotactile biofeedback (BF) system which augments information regarding the user's foot pressure to enhance gait performance. The effects of the proposed system on the gait patterns of healthy older adults and on the cognitive load during gait were evaluated; these factors are essential to clarify feasibility of the device in real-life settings. The primary task of our study was to evaluate gait along with a cognitively demanding activity in 10 healthy older adults. Regarding kinematic and kinetic data in the BF condition, the subjects had significantly increased ankle dorsiflexion during the heel contact phase in the sagittal plane and marginally increased foot pressure at the toe-off and stride length. However, such kinematic and kinetic changes were not attributed to the increased walking speed. In addition, cognitive performance (i.e., the number of correct answers) was significantly decreased in participants during gait measurements in the BF condition. These data suggest that the system had the potential for modifying the kinematic and kinetic patterns during walking but not the more comprehensive walking performance in older adults. Moreover, the device appears to place a cognitive load on older adults. This short report provides crucial primary data that would help in designing successful sensory augmentation devices and further research on a BF system.

Balance Training With a Vibrotactile Biofeedback System Affects the Dynamical Structure of the Center of Pressure Trajectories in Chronic Stroke Patients.

Haptic-based vibrotactile biofeedback (BF) is a promising technique to improve rehabilitation of balance in stroke patients. However, the extent to which BF training changes temporal structure of the center of pressure (CoP) trajectories remains unknown. This study aimed to investigate the effect of vibrotactile BF training on the temporal structure of CoP during quiet stance in chronic stroke patients using detrended fluctuation analysis (DFA). Nine chronic stroke patients (age; 81.56 ± 44 months post-stroke) received a balance training regimen using a vibrotactile BF system twice a week over 4 weeks. A Wii Balance board was used to record five 30 s trials of quiet stance pre- and post-training at 50 Hz. DFA revealed presence of two linear scaling regions in CoP indicating presence of fast- and slow-scale fluctuations. Averaged across all trials, fast-scale fluctuations showed persistent dynamics (α = 1.05 ± 0.08 for ML and α = 0.99 ± 0.17 for AP) and slow-scale fluctuations were anti-persistent (α = 0.35 ± 0.05 for ML and α = 0.32 ± 0.05 for AP). The slow-scale dynamics of ML CoP in stroke patients decreased from pre-training to post-BF training (α = 0.40 ± 0.13 vs. 0.31 ± 0.09). These results suggest that the vibrotactile BF training affects postural control strategy used by chronic stroke patients in the ML direction. Results of the DFA are further discussed in the context of balance training using vibrotactile BF and interpreted from the perspective of intermittent control of upright stance.